Are these fish compatible?

This is a discussion on Are these fish compatible? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
I am looking to get a few different fish for my 75g tank. They all can live within the same temp and ph. But, ...

I am looking to get a few different fish for my 75g tank. They all can live within the same temp and ph. But, The Kh for these fish are at different levels. As my name suggests I am a fish noob. I have not tested for Kh ever. Will this stop me from integrating the fish I want?

KH refers to your temporary hardness aka carbonate hardness aka alkalinity. Fish are very adaptable, especially tank-bred/raised which is becoming more abundant these days. Those "ideal" conditions may only matter when breeding certain species. Some people try changing around their water chemistry using buffers and such but that can lead to horrible crashes down the road. It's best to drip acclimate newcomers to prevent any sort of shock.

I am looking to get a few different fish for my 75g tank. They all can live within the same temp and ph. But, The Kh for these fish are at different levels. As my name suggests I am a fish noob. I have not tested for Kh ever. Will this stop me from integrating the fish I want?

I have no idea about what kh are and what kh levels in my tank are. Living in Colorado my ph is naturally around 7.8.

If you are on municipal water you can get the numbers from the water treatment plant, perhaps they are posted on their website, others have been. I have very hard water with 23dGH and 21dKH but find that it tends to go lower in the tank depending on a few factors. Witha 7.8 I would assume (but don't know) that your water is on the hard side... maybe over 10dGH (GH is more important to know that KH but the test kit that measures one also measures the other). I chose fish that had ranges that included those levels assuming that I cold lower it somewhat by using reverse osmosis water as necessary to cut the hardness.

To say that fish are adaptable is a pretty board statement that needs some clarification. The ranges that are given are ideal ranges for the fish and some tank raised generations of fish can tolerate wider ranges but tolerating and thriving are two different things. So it comes down to a personal decision as to which conditions that you prefer to keep fish in, tolerating or thriving... of course there is also a third option, just keeping them alive... but I don't think that one applies here.

Now, aside from that, let's look at the list of fish you posted. There are some non-compatibles, for various reasons. At this point I am going to refer you to our fish profiles; each contains data on water parameters, tank sizes, numbers (some fish are shoaling and need groups), compatibility, etc. You can ask specific questions but please have a read of the fish profile. Profiles are under the second tab from the left in the blue bar across the top of the page. If the name in the profile is used identically in a post it will shade and you can click that for the profile pop-up. Example Cardinal Tetra, Denisons Barb. There are three rainbowfish profiles so far, and a couple pleco.

I am looking to get a few different fish for my 75g tank. They all can live within the same temp and ph. But, The Kh for these fish are at different levels. As my name suggests I am a fish noob. I have not tested for Kh ever. Will this stop me from integrating the fish I want?